1. Field of the Invention
The present invention relates generally to metal-to-metal seals for use in oil and gas wellbores, and specifically to metal-to-metal seals which are run into the wellbore and set against wellbore surfaces.
2. Description of the Prior Art
Wellbore completion operations frequently require the make-up of a high quality, gas-tight seals, between a workstring or production string and a wellbore tubular string, such as a casing string, which are intended for long service lives. Seals which include elastomeric components are subject to eventual deterioration after prolonged exposure to corrosive fluids and high temperatures. Also, when energized, elastomeric components are likely to flow along extrusion pathways if unchecked.
Furthermore, as prior art seal devices are lowered over great distances into oil and gas wellbores, elastomeric components are exposed to axial forces from fluids in the well, which sometimes cause the removal, or "swabbing-off", of the elastomeric component, severely impairing the operation of the seal.
Metal components can be used to obtain gas tight seals, but are generally suited for rather pristine environments other than wellbores. One problem with metal sealing components is that, like elastomeric components, metal sealing components will eventually become degraded after prolonged exposure to corrosive fluids.